Struct CsvReader 

pub struct CsvReader { /* private fields */ }

CSV file reader with streaming capabilities and decompression support

Reads CSV files row by row using an iterator pattern. Automatically handles compressed files (.csv.zst, .csv.gz, .csv.zip). Memory usage is constant and low.

Examples

use excelstream::csv_reader::CsvReader;

let mut reader = CsvReader::open("data.csv").unwrap();

for row_result in reader.rows() {
    let row = row_result.unwrap();
    println!("{:?}", row);
}

With Headers

use excelstream::csv_reader::CsvReader;

let mut reader = CsvReader::open("data.csv")
    .unwrap()
    .has_header(true);

if let Some(headers) = reader.headers() {
    println!("Headers: {:?}", headers);
}

for row_result in reader.rows() {
    let row = row_result.unwrap();
    // Process data rows (header already consumed)
}

Implementations

impl CsvReader

pub fn open<P: AsRef<Path>>(path: P) -> Result<Self>

Open CSV file - auto-detects compression from file extension

File Extensions

• .csv → Uncompressed, direct read
• .csv.zst, .csv.zip → Zstd decompression
• .csv.gz → Deflate/Gzip decompression

Examples

use excelstream::csv_reader::CsvReader;

// Plain CSV
let reader = CsvReader::open("data.csv").unwrap();

// Compressed CSV (auto-detected)
let reader = CsvReader::open("data.csv.zst").unwrap();

pub fn delimiter(self, delim: u8) -> Self

Set custom delimiter (builder pattern)

Examples

use excelstream::csv_reader::CsvReader;

let reader = CsvReader::open("data.csv")
    .unwrap()
    .delimiter(b';');

pub fn quote_char(self, quote: u8) -> Self

Set custom quote character (builder pattern)

pub fn has_header(self, has: bool) -> Self

Indicate that the first row contains headers (builder pattern)

When set to true, the first row will be stored and accessible via headers(). The iterator will skip the header row.

pub fn headers(&self) -> Option<&[String]>

Get header row if available

Returns Some(&[String]) if headers were parsed, None otherwise.

pub fn read_row(&mut self) -> Result<Option<Vec<String>>>

Read a single row

Returns Ok(None) when EOF is reached.

Examples

use excelstream::csv_reader::CsvReader;

let mut reader = CsvReader::open("data.csv").unwrap();

while let Some(row) = reader.read_row().unwrap() {
    println!("{:?}", row);
}

pub fn rows(&mut self) -> CsvRowIterator<'_>

Get iterator over rows

Examples

use excelstream::csv_reader::CsvReader;

let mut reader = CsvReader::open("data.csv").unwrap();

for row_result in reader.rows() {
    let row = row_result.unwrap();
    println!("{:?}", row);
}

pub fn row_count(&self) -> u64

Get the number of rows read so far